Ferguson said: "To begin with, when I first started out in management 37 years ago there were no agents. Imagine that! There was no freedom of contract either, so players were totally tied to their clubs.

"A change in that sense was inevitable, though I think that now the scales tipped completely in the other direction and I'm not sure it's good for the game.

"Of course the way the media works has changed too, there's a lot of pressure on journalists to publish huge news stories - not just about sport but about everything - and that's had an impact on us, no doubt about it."

When asked what the secret behind his longevity at United was, Ferguson said:

"It has a lot to do with the club. I've had the opportunity to work with a more long-term view and change direction towards where I think it should go. I can plan two or three years ahead, which is something that doesn't happen hardly anywhere else.

"This is a results industry and if a manager loses four or five games in a row then his job is under threat. But at United that scenario simply isn't possible. I'm in charge of all footballing matters, including our scouting network and youth teams. In that sense I'm very fortunate, because I can make quick decisions on who to bring in next to strengthen the squad and where to get them from."